The invention relates to an inclined-axis variable displacement unit or an axial piston machine of inclined-axis construction.
The generally known operating principle of such machines is based on an oil-volume stream being converted into a rotary movement.
A cooling arrangement is particularly important in axial piston machines of inclined-axis construction, in particular when relatively high levels of power are to be transferred. Insufficient cooling adversely affects the service life since the signs of wear increase at high operating temperatures. Moreover, with improved cooling, higher rotational speeds and larger maximum external diameters of the bearings are possible, these factors being of considerable importance as far as the service life of axial piston machines is concerned.
Axial piston machines of inclined-axis construction in which the bearings are cooled by oil which is located in the housing of the machine are already known. The oil here is fed on by a pump effect which is produced by the rotation of the roller mounting. A disadvantage of this solution, however, is that it is essentially only the oil which is located in the immediate vicinity of the mounting and is already at elevated temperature which is circulated. Moreover, this oil has already cooled other internals of the machine beforehand, with the result that the viscosity has already been reduced, an elevated oil temperature resulting in a reduction in the viscosity.
Patent DE-A-196 49 195 discloses a cooling arrangement for an axial piston machine in which the operating medium is guided, from a low-pressure branch of the main circuit of the motor, through a cooling channel which extends in the central part of the cylinder block and along the axis of rotation of the shaft. A disadvantage of this solution, however, is that the oil is likewise heated en route to the bearings in the central part of the motor. Moreover, this arrangement of a cooling channel restricts the throughflow cross section to a considerable extent, with the result that the quantity of oil flowing through for cooling is vastly reduced.
Finally, Patent DE-A-198 29 060 discloses a means for cooling an axial piston machine in which the oil used as coolant is introduced directly at the mounting. The coolant then passes through the mounting into the housing interior, in which the cylinder drum is located. In this case, a branch line runs from the coolant stream along the axis of rotation of the shaft and then through the central part of the cylinder block. However, this line, rather than being provided for cooling purposes, is only provided for lubricating the synchronizing articulation.
The principal object of the present invention is to provide an inclined-axis variable displacement unit or an axial piston machine of inclined-axis construction in which the service life is increased.
This object is achieved by an inclined-axis variable displacement unit or an axial piston machine of inclined-axis construction.
An inclined-axis variable displacement unit has an output shaft (1), mounted in a housing (4), and a cylinder block (10), the cylinder block (10) being connected to the output shaft (1) via a synchronizing articulation (13), and via working pistons (11) which can be displaced in the cylinder block (10), and the cylinder block (10) being mounted in a pivoting body (5) which can be pivoted in relation to the axis of the output shaft, it being the case that the pivoting body (5) is in the form of an open vessel, and the cylinder block (10) is arranged in the opening of the pivoting body.